Public Release: 22-Oct-2013
Flu shot halves risk of heart attack or stroke in people with history of heart attack, study finds

TORONTO, ON, October 22, 2013 -- The flu vaccine may not only ward off serious complications from influenza, it may also reduce the risk of heart attack or stroke by more than 50 per cent among those who have had a heart attack, according to new research led by Dr. Jacob Udell, a cardiologist at Women's College Hospital and clinician-scientist at the University of Toronto. What's more, the vaccine's heart protective effects may be even greater among those who receive a more potent vaccine.

"Our study provides solid evidence that the flu shot helps prevent heart disease in vulnerable patients --with the best protection in the highest risk patients," Dr. Udell said. "These findings are extraordinary given the potential for this vaccine to serve as yearly preventative therapy for patients with heart disease, the leading cause of death among men and women in North America."

Published today in the Journal of the American Medical Association, the study reviewed six clinical trials on heart health in people who received the flu vaccine. The studies included more than 6,700 patients with a history of heart disease. The researchers found people who received the flu shot:

Had a 36 percent lower risk of a major cardiac event (heart attack, stroke, heart failure, or death from cardiac-related causes) one year later

Had a 55 percent lower risk of a major cardiac event if they had a recent heart attack

Were less likely to die from cardiac-related and other causes, and

Were less likely to have a major cardiac event with a more potent vaccine compared with the standard seasonal vaccine

Dr. Udell carried out this research in collaboration with Dr. Michael Farkouh, senior co-author of the study and Chair of the Peter Munk Centre of Excellence in Multinational Clinical Trials, which is within the Peter Munk Cardiac Centre at the University Health Network.

"If the flu vaccine can reduce the risk of cardiac events, these shots could have considerable impact on cardiac health," said Dr. Udell. However, Drs. Udell and Farkouh caution that a large prospective clinical trial is necessary to confirm the effectiveness and safety of the influenza vaccine as a therapy that will reduce the risk of heart attack or stroke in people with heart disease. The researchers are now organizing this type of clinical trial to follow heart disease patients for up to 12 months after receiving the flu shot.

"These findings are all the ammunition we need to move forward," said Dr. Farkouh, who is also director of the Heart and Stroke Richard Lewar Centre at the University of Toronto. "We'll build on this research with a definitive, international trial to conclusively determine whether the flu shot prevents heart attack."

If proven to be a safe and simple prevention method, the impact could be significant for people with or at risk of heart disease and stroke.

"Hundreds of thousands of people die each year from cardiac causes in North America," Dr. Udell said. "While preventative care involves lifestyle changes and taking your pills, now, we may also be able to tell patients by getting your flu shot, it might save your life - what a simple and significant way to reduce deaths and the burden on our healthcare system."

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Women's College Hospital (http://www.womenscollegehospital.ca) is advancing the health of women and improving healthcare options for all by delivering innovative models of ambulatory care. Fully affiliated with the University of Toronto, the hospital is Canada's leading academic, ambulatory hospital and a world leader in women's health. With more than 800 physicians, nurses and health professionals, the hospital offers a range of specialized clinics and programs that are bridging the gaps in the health system. Women's College Hospital is helping to keep people out of hospital by being at the forefront of cutting-edge research, diagnosis and treatment that will help prevent illness and enable patients to manage their health conditions. This healthcare enables Canadians to live healthier, more independent lives. At the Women's College Research Institute, scientists combine science and patient care to develop innovative solutions to today's greatest health challenges.

About The Peter Munk Cardiac Centre

The Peter Munk Cardiac Centre is the premier cardiac centre in Canada. Since it opened in 1997, the Centre has saved and improved the lives of cardiac and vascular patients from around the world. Each year, approximately 55,000 patients receive innovative and compassionate care from multidisciplinary teams in the Peter Munk Cardiac Centre, and the Centre trains more cardiologists, cardiovascular surgeons and vascular surgeons than any hospital in Canada. The Centre is based at the Toronto General Hospital and the Toronto Western Hospital - members of University Health Network, which also includes the Princess Margaret Cancer Centre and Toronto Rehabilitation Institute. All four sites are research hospitals affiliated with the University of Toronto. For more information please visit http://www.petermunkcardiaccentre.ca

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